Device for regulating mixed fluid temperatures



1951 w. L.. VINSON 2,569,838

DEVICE FOR REGULATING MIXED FLUID TEMPERATURES Filed June 17) 1946 2Sheets-Sheet 1 IIIJYIEFGI 741 HARRIS/(16571: FosrERf/flRR/s gig/ 7x11 FOR THE FIRM A rroAwEys Patented Oct. 2, I951 DEVICE FOR REGULATINGIWIXED FLUID TEMPERATURES Walter L. Vinson, Sherman Oaks, Calif.

Application June 17, 1946, Serial No. 677,243

12 Claims. 1

My invention relates in general to the art of regulating fluidtemperatures and, more particularly, to an automatic device which isadapted to regulate the temperatures of fluids by mixing fluids ofdifferent temperatures, and which is adapted to maintain the temperatureof a mixture of the fluids at a substantially constant and predeterminedvalue.-

Reference is hereby made to my application Serial No. 677,244, filedJune 17, 1946, and entitled Fluid Temperature Regulator, now abandoned,and to my application Serial No. 744,395, filed April 28, 1947, andentitled Temperature and Flow Regulator, now Patent No. 2,526,099, datedOctober 17, 1950.

In general, my invention involves introducing fluids of differenttemperatures into a common mixing chamber in such proportions that amixture of a predetermined temperature is produced, the properproportions preferably being obtained by regulating the relative ratesof flow of the fluids into the mixing chamber in response to thetemperature of the mixture, which is a primary object of my invention.

Another object of my invention is to provide 'a device having inletcontrol means responsive to the temperature of the mixture forregulating the rate of flow of one or more of thefluids into the mixingchamber, the inlet control means preferably including mixing valve meansfor regulating the relative rates of flow of the fluids, and includingmeans responsive to the temperature of the mixture for operating andregulating the position of the mixing valve means to maintain themixture temperature at a substantially constant and predetermined value.

, Still another object of the invention is to provide means for varyingor adjusting the temperature at which the mixture is maintained by theinlet control means so that any desired mixture temperature may beobtained within the tem-, perature range defined by the maximum andminimum fluid temperatures.

My present invention provides a device of the foregoing generalcharacter wherein the mixing valve means includes a mixing valve whichis reciprocable in the mixing chamber to regulate the relative rates offlow of the fluids therein, the reciprocation of the mixing valve beingeffected by the temperature responsive means which preferably includes athermostatic element which is adapted to expand or contract in responseto variations of the mixture temperature to reciprocate the mixingvalve, thus regulating the relative rates of flow of the fluids into themixing chamber to maintain the mixture temperature substantiallyconstant at a predetermined'tilue. A related object is to provide suchan expansible thermostatic element which is adapted to expand orcontract an initial amount before moving said mixing valve so that theparticular temperature at which the mixture is maintained may beadjusted by varying the amount of initial expansion or contraction ofthe thermostatic element.

The expansible thermostatic element preferably comprises an expansiblereservoir, such as a bellows, having an operating fluid therein which isadapted to expand or contract in response to mixture temperaturevariations to regulate a dimension, preferably the length, of thethermostatic element, and, consequently, the operation of the mixingvalve. An important object of my invention is to provide a secondaryreservoir which is connected to the expansible reservoir and which isalso filled with the operating fluid, the secondary reservoir preferablybeing an annular container which surrounds the expansible reservoir. Theemployment of the secondary reservoir permits the use of alarge body ofoperating fluid so that the volume changes of the operating fluid for agiven temperature change are increased, thus increasing or amplifyingthe amount of expansion or contraction of the expansible reservoir for agiven temperature change, which is another important object of myinvention. Such amplification of the amount of expansion or contractionof the expansible reservoir permits the use of a smaller reservoir andprovides for more accurate and sensitive response to temperaturechanges.

Still another important object of my invention is the provision of atemperatureregulating device which automatically diverts or by-passesthe mixture until the temperature thereof approaches or is substantiallyequal to the predetermined value.

I prefer to provide a device of this general character having by-passand service outlets and having outlet control means responsive to thetemperature of the mixture for regulating flow of the mixture throughthe by-pass and service outlets, which is another object of theinvention. A related object is to provide a temperature regulatingdevice wherein the outlet control means is actuable hydraulically by themixture in response to the temperature thereof.

A further object is the provision of outlet control means includinghydraulically-actuable outlet valve means for such that the outlet valvemeans automatically directs the mixture'through the. by-Dass'outletuntil the mixture temperature approaches. the. predetermined value andautomatically directs the mixture through the service outlet only whenthe mixture temperature is substantially equal to the predeterminedvalue. Thus, myinvention insures that the mixture delivered at theservice outlet will always be at the desiredtemperature;

An additional object of my invention isto provide means for regulatingthe inlet pressuresof the fluids to minimize pressure fluctuations: atthe inlet control means; The pressure regulating means providessubstantiallyconstant inlet pressures at the inlet control means bycompensating-for inlet pressure variations, thus. minimizing flow.variations'which would result from such pressure variations.Consequently, the. inlet..control means is primarily concernedwithcompensating for temperature; fluctuations, and any compensationfor.pressurefluctuations by the inletcontrol :means. isminimized, thusproviding for more uniform'and reliable temperature-regulation.

Another object of my: invention, is the. provision eta-temperatureregulating, device which may be operated by -means of a singlevalvewhich is adapted to regulate flow of the mixture, from the mixingchamber.

The foregoing objects and advantagesoiv my invention; togetherwithvarious. other objects and advantages which will. beevidenthereinafter, may be realized by meansof the exemplaryembodiment-which. is described. indetail hereinafiter and is illustratedinv the accompanying drawings..- The embodimentillustrated is.particularly adapted'for regulating the temperature ofa shower by'mixingwater from the hot? and "colcl--- water lines in, suitable. proportionsto maintain the. temperature. of the shower sub.- stantially constant ata, predeterminedv value, and will be considered in thisconnection forconvenience. in disclosing the invention. However, it will.be-understood that the, embodiment illustrated is susceptible. tovvarious other applications, and- I do not, intendto be; limited, to .theparticular application considered. hereinafter- Referring to the. drawins, which are intended as illustrative only:

Fig. l is a sectional view ofa temperature, regulating device whichembodies the fundamental principles of my invention, and which is takenalong thebroken line l-l of Fig. 2 in the direction indicated by thearrows contiguous thereto;

Fig. 2 is a sectional view thereof which, is taken along the broken line2-2.of.Fig. l in the direction indicated by the arrows. contiguous,thereto;

Figs. 3, 4, and are; sectional views. which are taken" along the brokenlines 3-4, 4-4, and 55, respectively, of Fig. 1,;

Fig. 6 is a fragmentary-sectional view which is taken along thee-brokenline 66 ofFig. 1 in the; direction indicated by the arrows contigu- Qus:thereto Fig. 7 is a sectionalyview which is .taken'along :the brokenline -1'|of Fig. 6;.

Fig. 8 isafragmentary sectional viewof a mixing valve means;

Fig. 9 is an enlarged, sectional view of a control valve means which istaken along the broken line 99 of Fi 1;

Fig. 10 is a sectional view of the control valve means which is takenalong the broken line I0--l0 of Fig, 9; and

Fig. 11 is a utility view illustrating a shower installation whichincorporates the temperature regulator.

Referring particularly to Figs.'1 and2 of the drawings, the temperatureregulating device includes a casing or housing l5 which is formed in,three major sections in the particular constructionillustrated, forconvenience in manufacturing the device. The housing I5 includes aninletsection or inlet manifold I6, a cylindrical intermediate or mixingsection I1, and an outlet section oroutlet manifold I8, the inletmanifold having inlets or inlet passages 20 and 2| therein whichcommunicate with a cylindrical mixing chamber22 in themixing section,and the outlet manifoldhaving a by-pass outlet 23 and a service outlet24 therein which communicate with. the mixing chamber through an outletpassage 25. The. device includes inlet control means 21 dis.- posed inthe mixing chamber 22 for regulating flow of the fluids .into. themixing chamber from the inlets 20 and 2| inresponse to the mixturetemperature, the inlet control means including reciprocable. mixingvalve means .28 for regulating flow of the fluids into the mixingchamber, and includingmeans 29 responsive to the temperature of themixture in themixing chamber foroperating the mixing valve means tomaintain the mixture temperature, substantially constantat.apredetermined value. The device is preferably provided with means 30for regulating the pressuresof'the fluids in the inlets 20 and 2| to.minimize any flow variations through the mixing. valve means 28 whichwould otherwise result from inlet .pressure fluctuations, therebyreducing the temperature compensation required of the temperatureresponsive means 29. In order to permit variations of the predeterminedmixturetemperature, I prefer to provide means 32 associated with, thetemperature responsive means29 for varying or adjusting thetemperatureat which the mixture is maintained by the temperatureresponsive means.

Inorder to. regulate the. rate at which the fluid. mixture is delivered,by the temperature regulating. device, the device is preferably providedwith service valvemeans 33 for regulating the rate of flow of themixture through the outlet. passage 25,. the service valve, means beingmanually operable in the particular construction illustrated. Themixture flowing through the. outlet passage 25 is directed througheither the by-pass outlet 23 or the service outlet 24 by outlet controlmeans. 34in response to the mixture temperature, the mixture beingdiverted through the by-pass. outlet unless the temperature thereof issubstantially equal. to the predeterminedvalue. The outlet control means34 includes. hydraulically-actuable outlet .valve means: 35-fordirecting the mixture through either the by-pass or service outlets 23or 24, the operation of the outlet valve means being regulated. bycontrol means, or, control valve means 36 in response to the mixturetemperature. Thecontrol valve means 36 is preferably employed foractuating the control valve means if desired,

Considering the construction of the temperature regulating device inmore detail, the inlet manifold I6 is provided with a bore 40 thereinwhich receives an end 4| of the mixing Section H of the housing I5, theinlet manifold and mixing section being threadedly interconnected. Theoutlet manifold I8 is provided with a bore 23 therein which receives theother end 44 of the mixing section H, the outlet manifold and mixingsection being threadedly interconnected. For convenience in mounting thetemperature regulating device on any suitable supporting structure suchas a wall (not shown), the outlet manifold l8 may be provided with oneor more attachment flanges 48 each having a hole 49 there through for abolt or the like as best shown in Fig. 2.

. Fluids of different temperatures are introduced into the mixingchamber 22 through the inlet passages 20 and 2|, the fluid having thehigher temperature, 1. e., the hot fluid, being introduced into theinlet 20 in the particular construction illustrated, and the fluidhaving the lower temperature, i. e., the cold fluid, being introducedinto the inlet 2|. The fluids may be introduced into the inlets 20 and2| through inlet fittings 52 which may be connected to suitable fluidsupply lines 54 and 55 shown in Fig. 11, in the usual manner, the inletfittings being secured to the inlet manifold IE by bolts 53 as bestshown in Fig. 3. The bolts 53 extend through openings 56 in the inletmanifold IE and are threadedly inserted in openings in the fittings 52as is well known in the art.

As best shown in Fig. 8, a tubular sleeve or bushing 51 is disposed inthe mixing chamber 22, the bushing having a relatively wide annular,groove or inlet 58 in the outer surface thereof, and a similar annulargroove or inlet 59 in the inner surface thereof. The bushing 51 isprovided with a pair of relatively narrow inlets or inlet slots 60therethrough which communicate with the annular groove 58, and isprovided with a relatively narrow slot 5| therethrough whichcommunicates with the annular groove or inlet 59.

As best shown in Fig. 8, the mixing section I1 is provided with a pairof relatively narrow, transverse slots 62 and 63 therethrough, the slot62 being adapted to provide fluid communication between the inlet 20 andthe mixing chamber 22 through the annular groove 58 and inlets 60, andthe slot 63 being adapted to provide fluid communication between theinlet 2| and the mixing chamber through the slot 5| and the annulargroove or inlet 59 The mixing valve means '28 includes a hollow,cyclindrical mixing valve 65 which is reciprocably disposed in thetubular bushing 51. The annular grooves or inlets 58 and 59 in thebushing 51 permit the hot fluid from the inlet 20 and the cold fluidfrom the inlet 2|, respectively, to circulate entirely around the mixingvalve 65 so that the net lateral forces exerted thereon by the-pressuresof these fluids are equal to zero. This balanced construction minimizesfriction on the mixing valve 65 and insures smooth operation thereof,which is an important feature of my invention.

As best shown in Fig. 8, the mixing valve 65 is provided with a pair ofnarrow, elongated, transverse ports or slots 66 therein, and a pair ofsimilar ports or slots 61 therein, all of which communicate with theinterior 68 thereof. The

6. ports 66 are adapted to register with the inlets 60 to admit hotfluid from the inlet 20 into the mixing chamber 22, and the ports 61 areadapted to register with the inlet 59 to admit cold fluid from the inlet2| into the mixing chamber. As best shown in'Fig. Z, a screw 69 extendsthrough the inlet manifold I6 into a longitudinal slot 69a in the mixingvalve 65 to prevent rotation of the mixing valve during reciprocationthereof. As will be apparent from Fig. 8, the relative positions of theinlets 60 and 59 and ports 65 and 51, respectively, are such that whenthe ports 65 fully register with the inlets 60, the ports 61 are justout of registry with the inlet 59, and when the ports 61 fully registerwith the inlet 59, the ports 66 are just out of registry with the inlets60. This arrangement of the inlets 65 and 59 and the ports 66 and 51,together with the elongated configuration thereof, provides extremelysensitive regulation of the relative rates of flow of the hot and coldfluids since the mixing valve 55 need be moved through only a very smalldistance by the temperature responsive means 29 to change the relativerates of flow of the hot and cold fluids appreciably. Thus, if themixture temperature fluctuates because of variations of the temperatureof either the hot or cold fluid, or because of variations of the flowrate of either fluid which result from inlet pressure variations, thetemperature responsive means 29 need move the mixing valve 65 throughonly a small dis-' tance to compensate for such mixture temperaturefluctuations, thus insuring sensitive and rapid regulation of themixture temperature.

Considering the construction of the mixing valve means 28 in moredetail, the mixing valve 65 includes an end wall 1!] which is providedwith a plurality of openings or ports 1| therein which permit the mixedfluids in the interior 68 of the mixing valve to flow therefrom intothat portion of the mixing chamber 22 which contains the temperatureresponsive means 29. The end wall 10 of the mixing valve 65 is providedwith a projection or boss 12 thereon having a bore 13 therethrough for areciprocable rod member or plunger 14 which forms part of thetemperature adjusting means 32 as will be described in detailhereinafter.

The temperature responsive means 29 includes an expansible thermostaticelement 11 which is adapted to expand or contract longitudinally inresponse to variations of the mixture temperature, the thermostaticelement preferably including an expansible reservoir 18, such as thebellows illustrated, having an operating fluid therein which is adaptedto expand or contract in response to the mixture temperature to regulatethe length of the expansible reservoir. Any desired operating fluid maybe employed, the operating fluid preferably having a relatively highcoefficient of expansion. The temperature responsive means 29 alsoincludes a secondary reservoir 19 which is connected to the expansiblereservoir 18 by a head member or fitting which provides fluidcommunication therebetween, the secondary reservoir also being filledwith the operating fluid. As best shown in Fig. 1, the secondaryreservoir 19 includes a pair of concentric tubular members 82 and 83having an annular space 84 therebetween for the operating fluid, thetubular members being secured to the fitting 8D and to another fitting85 which is attached to the boss 12 on the mixing valve 65.

The fitting 80 is provided with a boss 81 thereonwhich is slidablydisposed in,a longitudinal bore fl in the outlet maniiold t8, the

fitting having a longitudinal bore 99- theretli rough which communicateswith the expansible reserv-oir'lll. As best shown in Fig. 1., thefitting 89 is also provided'with' a passage 99 therein. whichcommunicates with the secondary reservoir 19 andthe bore 89to'providefluid com-- munication between the expansible reservoir 18 andthe secondary reservoir. The expansible reservoir 18' and secondaryreservoir 19: may be filled with theoperating fluid through the bore-89' during assembly of-the temperature regulating, device, thebore thenbeing sealed in any suitable manner, as by a plug 9|.

As best shown in Fig.8.. 1 and 5, a plate'member 9 2- is-mounted on thefitting 80 and encircles the boss 8? thereon, the plate memberbeingprovided with an arm 93 which is adapted to actuate the controlvalvemeans 35 as will be" described in d'cta-il hereinafter. In theparticularconstrue tion illustrated, a spring 94 encircles the boss 81 on thefitting 80 and is seated against-the outlet manifold ill-and the platemember 92 ,v the spring being adapted to urge'the mixing valveGi'downwardly as viewed in Fig. 1.

best shown in Fig. 1, one end of thethermo static elementl'l is securedto an end member Sihaving a stem 96 which is slidably disposedinwaubore- 97: in the plunger 14. The relative lengths of the stem 9%and bore 9'! are such that the end member 95 may move relative to theplunger 74' asthe thermostatic element Hex-- pands and contracts, andmay engage: the plunger 14 after the element has expanded -a::predetermined amount for reasons to be discussed hereinafter.

In order to admit the mixture into the annular space between theexpansible reservoir 18- and the secondary reservoir 19, thefltting' 85,which is attached to the mixing valve :65, is provided with a pluralityof. ports 98 therein as best shown in Fig. 1. The fitting 80 is providedwitha pl-urality of ports 99 therein, only one of which is shown in Fig.1, to permit the mixture to flow from the annular space between thereservoirs l8 and T9, the plate member 92' being-provided with aplurality of ports I90, best shown i-n'Fig 5, which register with theports 99.

In order to describe the operationof the mixing valve means 2-8 and thetemperature responsi ve means 29, the following operating conditionswill be assumed for convenience: (l) the operating fluid in. thereservoirs l8- and I9- is adapted to expand in' response to temperatureincreases; (.2) "the temperature of the shot fluid introducedinto' themixing chamber "22 through the inlet 291s normally above ambient airtem-' perature; and. (3') the temperature" regulating device is eitherbeing put into operation for'the first time, or is being put intooperation after an. appreciable time interval has elapsed since thepreceding use thereof, so that the temperature of the hot fluid in theinlet .29 and supply line 54 is less than the normal temperature thereofand may be substantially equal to the ambient air temperature. It willbe understood that these operating conditions have been assumed forillustrative'purposes only, and I do not intend to be limited thereto.

Prior to putting 'the temperature regulating device into operation byopening the service valve means 33 as will be described hereinafter, theexpansible thermostatic element 11' will. in -a position such as thatshowiirin"Fig; The mix- =ing valvewill also be mrztne position;

in 1 so thatthehot ports to register with the hot fluid inlets 69, andso that the cold fluid ports-61 are just out of registry with the coldfluid inlet59, the mixing valve beingv held in: this position by thespring 94. Consequently, upon: opening the service valve means 33,,nocold fluid can enter the mixing chamber 221mm. the cold. fluid inlet2|, the only fluid entering the mixing chamber being the fluid atreduced tem perature' from the hot inlet 20. As this cold fluid in thehot fluid inlet 29 and supply line 51- is displaced by hot fluid fromthe source of hot fluid: supply-(not shown), the temperature of thefluid entering. the mixing chamber 22' gradually increases, thus causingthe expansible thermm static element 11 to expand by expanding theoperating fluid in: the reservoirs l8 and 19. This expansion of theoperating fluid expands the" thermostatic element 11 an initial amounttoincrease the/lengththereof so that the end. member 95"engages theplunger 14, the positiona! the "plunger being fixed by thetemperature:ad ju'sting means 3Zas will be described hereinafter: Since the initialexpansion of thermostatic ele ment "is limited by the plunger 14,further expansion thereof results in movement of the valvemember '65against the spring 94, the movement of the valve member being upward asviewed in- Fig. 1. Consequently, the cold fluid ports 61 begin toregister with the cold fluid inlet 59 to ad mit cold fluid into themixing chamber 22. Thereafter, the expansible thermostatic element 11regulates the position of the mixing valve 65' to regulate the relativerates of flow of the hot and cold fluids into the mixing chamber so thatthe mixture temperature is maintained substantially constant at thepredetermined. value.

It will be apparent that. as the. mixture of the hot. .and cold. fluidsleaves the mixing valve 65 and flows through the ports -H into thatportion of the mixing chamber 22 which containsthe temperatureresponsive means-29, part of the mixture flows upwardly, as viewed inFig. 1, through the annular space between the secondary reservoir 19 andthe walls of the mixing chamher. The remainder of the mixture enters theannular space between the reservoirs l8 and 19 through the ports 98, andflows through the annular space and out through the ports 99 and 100.Thus, substantially the entire surface area of the reservoirs 18 and I9is exposed to the ."mixture to insure rapid response to any mixture tem.perature variations.

The secondar reservoir 19 provides means .101 amplifying the expansionor contraction of the expansible" thermostatic element 11, since as theoperating fluid in the expansible reservoir 18 and the secondaryreservoir expands, for example, some of the operating fluid in thesecondary reservoir is displaced and flows through the passage into theexpansible reservoir to amplify the expansion of the thermostaticelement. Simiilarly, as the operating fluid contracts, the volume of theoperating fluid in the secondary reservoir 19 decreases to provide spacefor some of the operating fluid in the expansible reservoir 18, therebyamplifying the resulting contraction of the expansible thermostaticelement 11. construction insures that the thermostatic element 11' willrespond accurately to even very small mixture temperature variations toprovide. an extremely sensitive temperature regulating'devioe.

It will be apparent that the thermostaticelemeat It will control themixing valve. -65 :to

I and .of the shuttle valve in the bore.

shuttle valve in opposite directions.

shuttle valve I02 will regulate the degrees to '9 pensate for anymixture temperature variations regardless of the cause of suchvariations, thus maintaining the mixture temperature substantiallyconstant at the predetermined value. Such mixture temperature variationsmay be due either to fluctuations of the temperatures of the hot and/orcold fluids, or to fluctuations of the inlet pressures of the hot and/orcold fluids which result in fluctuating flow rates through-the inlets 60and 59 and ports 66 and 61, respectively.

Although the thermostatic element 11 will actuate the mixing valve 65 tomaintain the mixture temperature substantiall constant regardless ofwhether the temperatures or inlet pressures of the fluids fluctuate, Iprefer tocompensate for inlet pressure fluctuations with the pressureregulating means 30 as will be described in detail in the followingparagraphs so that the functions of the thermostatic element are reducedto com- Densating for temperature fluctuations only.

The pressure regulating means 30 includes a shuttle valve I02 which isreciprocable in a bore I03 in the inlet manifold I6, the bore extendingtransversely of and communicating with the inlets 20 and 2| and beingclosed by a plug member I04. The shuttle valve I02 includes three spacedpiston or plunger-like elements I 05, I06, and I01 which areinterconnected by rods I08.

The piston elements I05 and I01 are recessed at H and III, respectively,to receive springs H2 and H3, respectively, which are seated against thebase Wall of the bore I03 and against the .plug member I04,respectively, the springs being "adapted to urge the shuttle valvetoward a central or neutral position. However, the shuttle valve I02 mayalso be used without the springs H2 and H3, if desired. The pistonelements I05 I06 provide a passage I I6 therebetween which is adapted toregister with the inlet 20, and the piston elements I06 and I01 providea passage II1 therebetween which is adapted to register with the inlet2|. As best shown in Figs. 1 and 4, the inlet manifold I6 is providedwith a'pair of web portions H8 and H9, the latter being provided withpassages I20 and I2I therein, respectively, which communicate with theinlets 20 and 2|, respectively, and communicate with the bore I03 behindthe piston elements I05 and I01, respectively, to regulate the positionIt will be apparent that any difference between the inlet pressureswhich are applied to the piston elements I05 and I01 by the hot and coldfluids in the inlets 20 and 2|, respectively, will regulate the positionof the shuttle valve I02 in the bore I03 since the pressures are appliedto the Thus, the

which the passages H6 and I I1 register with the inlets 20 and 2| inresponse to fluctuations in 'the relative inlet pressures of the hot andcold -fluids to equalize the pressures thereof at the mixing valve means28. If, for example, the inlet pressure of the cold fluid in the inlet2I should decrease for any reason, the shuttle valve I02 will move tothe right as viewed in Fig. 1, in response to the decreased pressure onthe piston element I01, to increase the resistance offered by theshuttle valve to the flow of the hot fluid and to reduce the resistanceto the flow of the cold fluid, thereby equalizing the pressures of thehot and cold fluids at the mixing valve means 28. Thus, the pressures ofthe hot and 1 cold fluids at the mixing valve means 28 are maintainedequal at all times so that the relative rates of flow of the hot andcold fluids into the mixing chamber 22 are not affected by inletpressure fluctuations. Consequently, the mixture temperature will not beaffected by inlet pressure variations and the only function of thetemperature responsive means 29 is to compensate for any temperaturevariations of the hot and/or cold fluids, thereby permitting thetemperature responsive means to operate under more stable conditions toinsure more accurate mixture temperature regulation. Moreover, it willbe apparent that by employing springs II2 and H3 which may be deflectedsufficiently, if the springs H2 and H3 are employed, the shuttle valveI02 may be employed as a shut-off if desired in the event of failure ofeither the hot or cold fluid supply. If the cold fluid supply shouldfail, for example, the piston element I05 will completely close the hotfluid inlet 20, thus preventing the hot fluid from flowing into themixing chamber 22 and then flowing back into the cold fluid inlet 2 lThe discussion thus far has disclosed how the temperature regulatingdevice maintains the temperature of the mixture constant at oneparticular predetermined value. In order to permit varying thetemperature at which the mixture ismaintained, I prefer to employ thetemperature adjusting means 32, the details of which are best shown inFigs. 2 and 3. The temperature adjusting means includes the plunger 14which is slidably disposed in a bore I25 in the inlet manifold I6, theplunger being reciprocable bymeans of a cam I26 on a, shaft member I21which is journaled in a counterbore I28 in the inlet manifold. The inletmanifold I6 is provided with a bore I29 having a fitting I30 threadedlyinserted therein, the fitting serving to retain the shaft member I21.Leakage of the mixture from the'mixing chamber '22 around the shaftmember I21 is prevented by packing I3I, the packing being retained by acollar I32 which is threaded into a bore I33 in the fitting I30. Theshaft member I21 is provided with an end I34 having an adjusting handleI35 mounted thereon and attached thereto by a screw I36. The adjustinghandle I35 includes a scale or dial portion I38 having indicia I39thereon, as best shown in Fig, 11, which represent various predeterminedmixture temperatures, the particular predetermined temperature for whichthe temperature adjusting means 32 is set being indicated by a pointerI40.

Whenever it is desired to change the temperature at which the mixture ismaintained, it is merely necessary to rotate the adjusting handle I35until the pointer I40 indicates the desired temperature. Rotating thehandle I35 causes the cam I26 to displace the plunger 14, thusregulating the position of the plunger with respect to the thermostaticelement 11 to adjust the temperature at which the mixture is maintained.Consequently, the position of the plunger 1-4 determines the length ofthe thermostatic element 11 at the instant it begins to displace themixing valve 65. Since the length of the thermostatic element 11 isproportional to the mixture temperature, it will be apparent that thelength of the thermostatic element at approximately the instant itbegins to move the mixing valve 65 determines the temperature at whichthe mixture is maintained.

Assuming for convenience that the thermostatic element 11 is adapted toexpand inresponse to a mixture temperature increase as in the '14 in thenew position, thus resulting in a higher .lnixture temperature.Similarly, if the amount of initial expansion is decreased by moving thePlllh s 4 upwa ql a viewed i 1, the thermostatic element 11 will expandsufficiently to hegin to close the hot fluid ports 66 and open the coldfluid ports 61 at a lower mixture temperature. Thus, the temperature atwhich the mixture is maintained by the thermostatic elem. t H may beadjusted by adjusting the amount 'ofinitial expansion thereof in theparticular construction shown.

The mpe a u e djus in m ans 32 is also a ted to permit ma al e u ati n ot to a certain extent to obtain a mixture temperature which is equal tothe temperature of the @9 9 flu in h c ld fl id i e 2 y c in the hotfluid ports 6t, and fully opening the cold fluid ports 61 manually, thisfeature being partieul'arly applicable to a shower installation in theevent that a cold shower, i. e., a shower temperature equal to thetemperature of the cold fluid the cold inlet 2I-, is desired. To permitsuch manual temperature regulation, the plunger I4 is provided with ashoulder I.4I thereon which is normally spaced from the wall IU of themixing .valve55, as best shown in Fig. 2. If a mixture temperature equalto the temperature of the cold mud in the inlet ZI is desired, it ismerely necessary to rotate the adjusting handle I35 until the shoulderI4I of the plunger I4 engages the wall i he i i %1 5 an d p a es t m xinvalve suiliciently to close the hot fluid ports 66 and to" br n he 9 9fluid or s nto complete registry with the relatively wide cold fluidinlet 59, the purpose oi the relatively wide inlet 59 being to insurethe flow of cold fluid from the inlet 2! for a id ran e f posi on of h ihs al d ih manual tem e ature regum ohh s only he d flui hem the co fluiin t Z m fl into the mixing chamber 22, the temperature responsive means25 being inoperative when the plunger 1-4 is in this position. It willbe apparent that, when the mixing valve 65 is displaced in this mannerto close the hot fluid ports 66, the arm 93 on the plate member 92 isalso displaced to actuate the control valve means 36, which thenactuates the outlet valve means 35 to permit the mixture to flow throughthe service outlet 24, as will be described in detail hereinafter.

After leaving the mixing chamber it, the mixture at the predeterminedtemperature flows through the service valve means 33 and into the outletpassage 25. As best shown in Figs. 6 and '7, the service valve means 33may include an ordinary ratatable valve member I45 which is adapted toengage a seat I45 to prevent flow into the outlet passage 25, the valvemember being rotatable manually in the construction illustrated by meansof a handle M1 to regulate flow or the mixture. Thus, the rate of flowthrough the tem- 'perature regulating device is regulated by the singlevalve member I45 by regulating the rate of flow of the mixture from theinixing'chambar 22 12 service outlet, the direetionbeing determined bythe outlet control means 34. As best shown Figs. 1 and 2 the outletvalve means '35, which is part of the outlet control means -34, includesa reciprocab'le outlet valve I50 having an annular flange I5I which isadapted-to seat against either of a pair of valve seats I52 and 153, thevalve seat I52 being fo-rmed-inthe outlet man-fluid 48 and the valveseat I 53 being formed on a fitting I54 which is threadedly inserted ina bore I5f5 in the outlet manifold. The outlet valve includes-a plungerI51 which is operable in a cup or cylinder I58 formed the fitting I54,and includes a second plunger or stem I59 which is operable in a boreI60 in the outlet. manifold- I8, the outlet valve being provided with alongitudinal-l bero PM From the outlet passage 25, the mixture may 3therethrough for a reason to be discussed here'- inafter. The stem I59is encircled by a spring I52 which normally holds the annular flange I5| of the outlet va1ve I5Il against the valve seat I 53 as shown in Fig.2, to close the service outlet 24 so that the mixture flows from theoutlet passage 25- into the by-pass outlet 23, a by-pass line [63 beinconnected to the by-pass outletv to dispose of the mixture flowingtherethrough. As will? be described in detailhereinafter, the control.valve means 36 is adapted to displace the outlet valve I50 into. theposition shown in Fig. I to close the by-pass outlet 23 so that themixture flows through the service outlet. 24, passages I164 beingprovided in the fittin I54 to-permit the mixture to flow past thecylinder I58. A service line I615 is threadedly connected to the fittingI54 by a fitting 166, the service line leading to the point Where themixture is .to be used.

The control valve means 36. may convenientit be considered in connectionwith a specific. illustration of the operation of the outlet controlmeans 34', it being understood that. I. do not intend to be limited tothe particular illustration employed hereinafter. For example, if thetemperature regulating device is put into operation, for the first time,or is used after a considerable time interval has elapsed since thepreceding use thereof, the temperature of the hot fluid in the inlet 2|)and the. supply line 54', and the temperature of the mixture in themixin chamber 22 maybe approximately equal to the ambient airtemperature. Consequently; when the service valvev means 33 is opened,the fluid leaving the mixing chamber 22 will be cold until displaced byhot fluid from the hot fluid supply line 54. Normally, the outlet valveI50 is in the position shown in Fig; 2 sothat the fluid leaving themixing chamber 22 is diverted into the by-pass outlet 23 and} isdisposed of in any suitable manner. The function of the control means 36is toadmit part of the mixture into the cylinder I58 through the boreIBllih the outlet valve I 50 so that the-mixture will act on the plungerI5'I to displace the outlet valve into' the position shown in Fig. 1when the mixture temperature reaches, or substantially reaches; hepredetermined value, thus closingthe by-pass outlet 23 and opening theservice outlet 24 when the predetermined mixture temperature has beenattained.

Considering the details of the control means 35, which are best shown inFigs. 1, 9-, and; 10, the control means includes a valve body I59 whichis ed 'ly e te a. ore tlfl'ih th out e hhh iql'd; I! d s taine y a ocnut If" th v l e b dy bei Pro de i h b "2 therein and. be nro ed wit aor H8 h r i w h c mm i at s. ith th he 1. 2 and wit the mixin chamber22. A valve member I14 is disposed in the bore I12 and is provided witha .slidable stem I15 having a tapered shoulder I16 thereon which isadapted to seal the port I13, the stem having a reduced portion I11which extends through and is smaller than the port so that part of themixture from the mixing chamber 22 may flow around the reduced portionand into the bore I12 when the port is not sealed by the shoulder I16.The stem I15 is provided with a head I80 thereon which serves as a seatfor a spring I Bl which normally urges the stem to the right, as viewedin Fig. 9, so that shoulder I16 seals the port I13, the spring beingseated against a plug I03 which is threaded into the bore I12 and issecured by a'lock nut I84.

Assuming that all of the fluid in the hot fluid inlet 20 and supply line54 which is at too low a temperature has been displaced by hot fluidafter the service valve means 33 has been opened, fluid at the propertemperature will begin to enter the mixing chamber 22 through the hot.fluid inlets and ports 60 and 66, which are in complete registry. Asthe mixture temperature increases to the predetermined value for whichthe temperature adjusting means 32 is set be cause of the introductionof hot fluid into the mixing chamber 22, the mixing valve 65 will bedisplaced by the thermostatic element 11 to open the cold fluid ports 61and close the hot fluid ports 66 the amounts required to maintain themixture temperature at the predetermined value. Such displacement of themixing valve 65 is communicated to the plate member 92 so that the arm93 engages the reduced portion I11 of the stem I15 of the. control valvemeans 36, as best shown in Fig. 1, thus displacing the stem to open theport I13 to permit part of the mixture in the mixing chamber 22 toenterthe bore I12 in the valve body I69 as the mixture temperatureapproaches or substantially equals the predetermined value. The mixturein the bore I12 flows through passages I88 in the valve member I14 andthrough openings I89 in the valve body I69 into an annular groove I90therein. From the annular groove I90, the mixture flows through apassage I9I in the outlet manifold I8, as best shown in Fig. 1, and theninto the cylinder I56 through the bore I60 in the outlet valve I50.The'pressure of the mixture is thus applied to the plunger I51 todisplace the outlet valve I50 into the position shown in Fig. 1 so thatthe mixture is directed into the service outlet 24.

Thus, it will be apparent that the mixture will be diverted through theby-pass outlet 23 until all of the cold fluid in the hot fluid inlet 20and all of the cold mixture in the mixing chamber 22 have been displacedand the predetermined mixture temperature has been attained. Once thepredetermined mixture -'temperature has been attained, the thermostaticelement 11 actuates the control valve means 36 which then supplies themixture to the cylinder I56 to actuate the outlet valve I50, thusdiverting the mixture from the bypass outlet 23 to the service outlet24. Consequently, the mixture is notdirected through the service outlet24 until the temperature of the mixture has been increased to, orsubstantially to, the value determined by the tem- -be obtained in thecase wherein wthefluidin the cold fluid inlet 2I and supply line 54 andthe mix:

outlet valve I50 if the device is mounted vertically as shown in thedrawings, it being understood. however, that the device need not bemounted in a vertical position. If the outlet valve I50 were displacedto the position shown in Fig. 2 by the spring I62 immediately after theservice valve means 33 is closed, the mixture in the service outlet 24and the service line I65 above the outlet valve I50 would be trapped andeventually would assume the ambient air temperature so that the initialflow during subsequent operation of the device would be either too hotor too cold depending upon whether the desired mixture temperature isabove or below the ambient air temperature. Assuming that the desiredmixture temperature is above ambient air temperature, for example, theinitial flow during subsequent operation would be too cold. 7

However, the operation of the outlet control means 34 is such that theoutlet valve I50 does not assume the position shown in Fig. 2immediately after the service valve means 33 is closed,

but moves slowly from the position shown in.

Fig. 1 to that shown in Fig. 2 so that all of the mixture above theoutlet valve may flow downwardly and out through the by-pass outlet 23before the outlet valve reaches the position shown in Fig. 2.Consequently, no fluid remains above the outlet valve I50, thuspreventing an initial flow at the wrong temperature during subsequentoperation.

In considering the operation of the outlet control means 34 as theoutlet valve I50 is displaced from the position shown in Fig. l to thatshown in Fig, 2, it is convenient to assume the case wherein the desiredmixture temperature is above ambient air temperature.- It will beapparent that the thermostatic element 11 will contract slowly so thatthe arm 93 disengages the reduced portion I11 of the stem I15 of thecontrol valve means 36 as the temperature of the mixture in the mixingchamber 22 decreases slowly. As the arm 93 disengages the stem I15, thespring I8I causes the shoulder I16 on the stem to seal the port I13,thus terminating communication between the mixing chamber 22 and theoutlet passage 25. Consequently, the mixture in the cylinder I58 willleak past the plunger I51 slowly to permit the outlet valve I50 to openthe by-pass outlet 23, there being suflicient clearance between theplunger and the walls of the cylinder to permit leakage at a small rate.Thus, the mixture in the service line I65 flows past the outlet valveI50 and through the by-pass outlet 23 before the outlet valve reachesthe position shown in Fig. 2 so that none of the mixture is trapped inthe service line. In Fig. 11, I show an application of the temperatureregulating device to a shower installation wherein a shower head I95 isconnected to the service line I65. In the particular shower installationshown, check valves I96 are connected in the hot and cold water supplylines 54 and 55 to prevent flow of hot water into the cold line, or viceversa, in the event of failure of either the cold or hot water supply.Although the mixing valve 65 and the shuttle valve I02 are adapted toperform this function as previously mentioned,

KECKW imeer to employ the check valves I96 in order to:avoid theclosetolerances which would be necessary if either the mixing or shuttlevalves were relied upon. Such close tolerances would not onlytincreasemanufacturing costs, but would in crease friction, thus reducing thesensitiveness .ofioperation of the mixin 'valve and shuttle valve inresponse to temperature and pressure fluctuations, respectively.

Anyone desirous of taking a shower need only openthe service valve means33 and rotate the temperature adjusting handle I35 until the pointer IIII indicates the desired temperature.

No water will be delivered to the shower head [95 until the temperatureof the mixture is substantially equal to the desired value, so that itis unnecessary to wait outside the shower until all of the cold water inthe device and in the hot water supply line 54 has been displaced by hot"water as is. the case with ordinary shower installations. All of thewater is diverted into the bypass line I63, which may be connected tothe shower-drainif:desired, until the temperature at- .tains the desiredvalue before any water is delivered to the shower head I95.

- After the mixture in the mixing chamber 22 attains the propertemperature, the temperature responsive means 29 actuates the controlvalve means 36 to admit water to the outlet valve means -35 so that theoutlet valve means closes the bypassroutlet'23 and opens the serviceoutlet 24 to deliver water at the proper temperature to the shower headI95. The temperature responsive .means 29%actuates the mixing valvemeans 28 to compensate for any fluctuations of the hot and 'coldwatertemperatures, thus maintaining the ,mixture temperature at the propervalue.

If the inlet pressure in either of the supply lines 54 and 55 shouldvary, the pressure regulating means 3!] compensates for such pressurevariations to maintain equal hot and cold water pressures at .the mixingvalve means 28, thus limiting the function of the temperature responsivemeans to "compensate for temperature fluctuations and makin for moreaccurate and sensitive regulation.

' Such pressure variations are likely to occur "frequently and atinopportune moments and may be dangerous in ordinary showerinstallations if the cold water supply should suffer a pressure dropbecause of the sudden application of another load on the cold waterline, such as a load resulting from turning on a lawn sprinkler system,for example. In ordinary shower installations, such cold water pressuredrops may increase the shower temperature to: a dangerously high valuedue to the sudden reduction of the cold water flow rate.

' My invention prevents such rises in the shower temperature even if thecold water supply should fail completely for any reason, either theinlet control means 2'! or the pressure regulating means 30 beingadapted to shut off the hot water supply almost instantaneously if thecold water supply should fail. Considering the inlet control means 21 inthis connection, a failure of the cold water result "in the applicationof zero pressure to the '18 ,piston element I 01 of the shuttle valveIIIZ S. th I:

the pressure of the hot water, would-ca se piston. element I05 .to.block the hot water 20; thus-shuttingofi the hot water-v 'I'h the inletcontrol means 27 or the pressure regulating means 30 may be relied uponto shut Ofithe 'hot water. should the cold water fail, thereby providing an important safety feature. I In the event that, asperson usingthe shower desiresflto' take a cold shower, or desires to finish withacold shower aftertaking arhot'tshower, it is merely necessary to rotatethe adjusting handle' I35 sufficiently .to close the hot portsv ificandopen the cold ports 61 by displacing the mixin valve 65 manually, aspreviously described,.-so that the temperature responsive means 25 isinoperative. The control valve means 35 is actuated simultaneously inthe manner previously described to operate the outlet valve means 35 sothat the water in the mixing chamber, which is now at the temperatureofthe cold water in the inlet 2|, may flow through the service outlet 24to the shower head I instead of being diverted-through theby-pass outlet25. v

Although I have discussed a specific application of my invention to ashower installation, I do not intend to be limited thereto since theinvention is susceptible to various installations wherein temperatureregulation, or flow regulation in response to temperature, are required.Moreover, I do not intend to be limited to the specific construction ofthe embodiment disclosed herein since various changes, modifications,and substitutions may be incorporated therein without departing from thespirit of the invention. Consequently, I hereby reserve the right to theprotection afforded by the full scope of my appended claims. I

I claim as my invention: 1. In a device for mixing fluids of differenttemperatures and for controlling the temperature and discharge of amixture of the fluids, the combination of: a housing providingrespective inlets for the fluids of different temperatures and providingby-pass and service outlets for the mixture; thermostatic meansassociated with said inlets for controlling the relative flows of saidfluids through said inlets to produce a mixture of controlledtemperature; adjustment means operatively associated with saidthermostatic means for changing said controlled temperature; and outletcontrol means operatively associated with said thermostatic means fordelivering said mixture to said by-pass outlet until the same is at atemperature differing from said controlled temperature by apredetermined amount, and for then flowing said mixture through saidservice outlet, said'outlet control means including ahydraulically-actuable outlet valve which is movable from a firstpositionwherein it closes said service outlet and opens said by-passoutlet to a second position.

'2. In a device for mixing fluids of difierent temperatures and forcontrolling the temperature of amixture of the fluids, the combinationof:

a housing provided with inlets for the fluids and provided with by-passand service outlets for the mixture; inlet control means responsivetothe temperature of themixture for regulating. the relazseaees ativerates of flow of the fluids into said housing; and, outlet control meansresponsive to the temperature of the mixture for regulating flow of themixture through said by-pass and service outlets, said outlet controlmeans including on outlet valve which is actuable by the mixture, andincluding control valve means for applying the pressure of the mixtureto said outlet valve.

. 3. In a device for mixing fluids of different temperatures and forcontrolling the temperature of a mixture of the fluids, the combinationof: a housing provided'with inlets for the fluids and provided withby-pass and service outlets for the mixture; inlet control means,including inlet valve means and including thermostatic means responsiveto the temperature of the mixture and mechanically connected to saidinlet valve means, for regulating the regular rates of flow of thefluids into said housing; outlet valve means operable by the mixture forregulating flow of the mixture through said by-pass and service outlets;and control valve means mechanically connected to and actuable by saidthermostatic means for regulating flow of the mixture to said outletvalve means to control the operation thereof.

' 4. A device as defined in claim 2, including service valve means forregulating flow of the mixture.

5. In a device for mixing fluids of diiierent temperatures and forcontrolling the temperature of a mixture of the fluids, the combinationof: a housing provided with a mixing chamber therein, and provided withinlets which communicate with said mixing chamber and which are adaptedto conduct the fluids of different temperatures thereinto; movable valvemeans for regulating flow of the fluids of different temperatures intosaid mixing chamber; means responsive to the temperature of the mixturein said mixing chamher for regulating the position of said valve meansto maintain the temperature of the mixture substantially constant at apredetermined value, said temperature-responsive means being adapted toexpand to move said valve means in response to 'an increase in thetemperature of the mixture, and being adapted to expand an initialamount before moving said valve means; and means for adjusting thepredetermined temperature value at which the mixture is maintained bysaid temperature-responsive means, said temperature-adjusting meansbeing adapted to vary said initial amount of expansion of saidtemperature-responsive means.

6. A device as defined in claim 5, wherein said temperature adjustingmeans includes stop means for limiting said initial amount of expansionof said temperature-responsive means, and includes means for varying theposition of said stop means.

'7. In a shower valve, the combination of a housing having inlets forhot and cold water, and having by-pass and service outlets for a mixturethereof; inlet valve means for regulating flow of the hot and cold waterthrough said inlets; means responsive to the temperature of the mixturefor regulating the operation of said inlet valve means to maintain themixture temperature at a predetermined value, saidtemperature-responsive means being connected to said inlet valve means;outlet valve means for regulating flow of the mixture through saidby-pass and service outlets; and control valve means for regulating theoperation of said outlet valve means so that said outlet valve meansdelivers the mixture through said by-pass outlet when the temperature ofthe mixture differs from said predetermined value thereof by more than apredetermined amount, and delivers the mixture through said serviceoutlet when the mixture temperature differs from said predeterminedvalue by less than said predetermined amount, said con- .trol valvemeans being in mechanically operative relationship with said temperatureresponsive means and being-movable to an open position thereby to applythe pressure of the mixture to said outlet valve means to operate itwhen the mixture temperature differs from said predetermined value -byless than said predetermined amount. r

8. In a device for controlling flow of a fluid, the combination of: ahousing provided with bypass and service outlets for the fluid; outletvalve means movable by fluid pressure applied to an area thereof from afirst position wherein it closes said service outlet and opens saidby-'- pass outlet to a second position wherein it opens said serviceoutlet and closes said by-pass outlet; control valve means for applyingfluid pressure to said area of said outlet valve means; thermostaticmeans exposed to the fluid and connected to said control valve means foroperating said control valve means to apply fluid pressure to said areaof said outlet valve means in response to an increase in the temperatureofthe fluid to a predetermined value; ,and'restricted passage means forslowly bleeding ofi the fluid pressure applied to. said area of saidoutlet valve means. 1

9. In a device of the character described, the combination of: housingmeans providing first and second outlets'ior a fluid mixture; spacedfirst and second valve seats respectively encom= passing saidfirstandsecond outlets; an outlet' valve movable between a firstposition wherein it is seatedon' said first valve seat to close saidfirst outlet and a second position wherein it is seated on said secondvalve seat to close said second outlet, said outlet valve being movablefrom said first position to said second position bya'fluid-pressure-force difierential impressed therea'cross: means fornormally biasing said outlet valve toward said first position; meansresponsive to the temperature of the fluid mixture for impressing afluid-pressure-force differential across said outlet valveto move itfrom said first position to said second position whenever thetemperature of the fluid mixture rises above a predetermined value, themeans last defined including a control valve movable to an open positionto impress said fluid-pressure-i'orce differential across said outletvalve, and including a thermostat exposed to the temperature of thefluid mixture and connected to said control valve for moving saidcontrol valve to its open position whenever the temperature of the fluidmixture rises above said predetermined value; and restricted passagemeans for reducing said fluidpressure-force difi'erential slowlywhenever the temperature of the fluid mixture falls below saidpredetermined value.

10. In a device for mixing a fluid of relatively low temperature and afluid of relatively high temperature, the combination of: housing meansproviding a mixing chamber and providing hightemperature andlow-temperature inlets which communicate with said mixing chamber andwhich are respectively adapted to conduct the high-temperature andlow-temperature fluids to said mixing'chamber: mixing valve means insaid housing means for regulating the relative rates of flow of thehigh-temperature andlow-temperature fluids into said mixing chamber,said" mixing valve means including'a mixing valve which is movablebetween a first position wherein it opens said high-temperature inletand closes said low-temperature inlet andasecond position wherein itcloses said high-temperature inlet and opens said low-temperature inlet;means for biasing said mixing valve toward said first position; means insaid housing means responsive to fluid'temperature variationsin saidmixing chamber for moving said mixing valve from said first positiontoward said second position in response to an increase in the fluidtemperature in said mixing chamber to a value higher than apredetermined minimumvalue, said biasing-means retaining said mixingvalve in said first position when the fluid temperature in saidmixingchamber is lower than said minimum value, said means responsive tofluid temperature variationsincluding' a thermostat exposed to thefluid' temperature in said mixing chamber, said thermostat having oneend connected'to said mixing valve and having a free end;- and: a stopcarried by said housing means andlengageabie by said free end ofsaid'thermostat as the fluid temperature in said mixing chamber attains"saidminimum value.

11. In a device for mixing xa'fluid of" relatively low temperature anda2 fluid of relatively'high temperature, the combination of: housingmeans providing a mixing chamber and providinghigl'rtemperature and lowtemperature-inlets which communicate said mixing chamber" and which arerespectively adapted to-- conduct the high-temperature andlow-temperature fluids to "said mixing chamber, said housing means alsoproviding by-passand service'outlets fora mixture of thehigh-temperature and low-tempera ture fluids; mixing valve means; insaid housing means for regulating'the relative rates of 'flow' of thehigh-temperature'and low-temperature fluids into said mixing chamber,said mixing valve means including a mixing; valve; which is movablebetween a. first position; wherein; it opens said high-temperature inletand" closes said low-temperature inlet anda second position wherein itcloses saidhi'gh temperatureinlet and opens said low-temperatureinIet;-- thermostat means in said housing means and responsive to fluidtemperature variations in saidmixing chamher for moving said mixing,valve from said first position toward said second position in responseto an increase in the fluid temperature in said mixing chamber to avalue higher than a predetermined minimum value so as to reduce therateof flow of the high-temperature fluid and to increase the rate offlow of 'the low-temperature fluid into said mixing chamber; outletvalve means movable by fluid pressure in said mixing chamber applied toan area thereof from a bypass position wherein it closes said serviceoutlet and opens said by-passoutlet to a service position wherein itopens said service outlet and closes said' by-pass outlet; control valvemeans movable from a closed position to an open position to expose saidarea of said outlet valve means to fluid pressure in said mixingchamber; and a 1 lost-motion connection between said thermostat meansand said control valve means, said lastmotion connection opening saidcontrol valve means when the fluid temperature in said mixing'chamberdifiers from said minimum value-by less than a'predetermined amount.

12. The device defined in claim 11 including restricted passage meanscommunicating with said area of said outlet valve means for" slowlybleeding off the fluid pressure applied to said area of said outletvalve means.

WALTER 1.; vINsoN:

REFERENCES orrsnf g The following" references are of record in-the fileof this patent:-

UNITED STATES PATENTS

